Stackit cockrings by Perfect Fit are made from stretchy, comfortable SilaSkin. These rings can be worn one at a time, or you can double up and add more for even more restriction. This Black Stackit ring is an instant classic and we love that it doubles over for even more tightness. These rings are ideal for balls or for using as a bumper and keep him harder for longer, prolonging his erection. They make his climax even more explosive and his partner will appreciate the extra playtime. You can use them with a water-based lubricant.